Q. The green power program offered by my utility is 65 percent "run-of-the-river hydroelectric" power. What is this? Is it much greener than what the utilities regularly offer? Is it my greenest water-derived power option? –Audrey, White Plains, NY

A. Imagine you’re a beaver, or a fish, or a tadpole, and you’ve made your cozy home in the same river ever since you were born. Now imagine a team of construction workers shows up and builds a huge concrete dam right in the middle of your home, leaving your once-fresh water stale and stagnant. Kind of a bummer, right? Large dams, while they do produce renewable energy, can interfere with water quality and fish migration, as well as degrade surrounding habitat.   That’s why run-of-the-river hydroelectric power, a technology that produces renewable energy without using dams to back water up, is in fact a better choice. The term “run-of-the-river” usually refers to power that’s generated from the force of water flowing from a high elevation to a lower one, using water’s natural flow. “Run-of-the-river is certainly considered better for aquatic wildlife and ecosystem management,” says Pierre Bull, policy analyst for the Natural Resources Defense Council.

Two drawbacks worth noting: One, there aren’t that many suitable places to build run-of-the-river projects (you’re in luck though—the Northeast is where most of the good spots are concentrated). And two, “run-of-the-river” is not an industry-regulated term. According to Fred Ayer, executive director of the non-profit Low Impact Hydropower Institute (LIHI), it’s not unheard of for power companies to try to greenwash their projects and call less-than-ideal hydro sites “run-of-the-river.” The LIHI does have a certification program for hydroelectric power, though—in order to be Certified Low Impact, a project must meet specific environmental criteria stipulating requirements for water quality and wildlife protection. If the hydro available to you isn’t certified, it’s worth giving the power company a call to quiz them on their environmental standards. Not only will it help you make your choice, it will help put the pressure on to provide truly green options.

Story by Sarah Schmidt. This article originally appeared in Plenty in November, 2008.

Copyright Environ Press 2008  

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